1 knot (kt) = 514.4444444 millimeter per second (mm/s).
Knot (kt) is a unit of Speed used in Standard system.
Millimeter Per Second (mm/s) is a unit of Speed used in Metric system.
Knots can be also marked as kn. 1 international knot = 1 nautical mile per hour. Millimeters per second also can be marked as mm/s and Millimetres per second(alternative British English spelling in UK).